std::sort is a template in C++. Which means that in most cases, I'd expect std::sort to inline the comparator and not have any function call overhead at all. (And even further: that the optimizer can make optimizations to std::sort + comparator together since they've been inlined)

So you have a good point. Function overhead is in qsort, not in std::sort. The line reads kinda nonsensically to me now that I think of it.